Renal Cell Carcinoma with Inferior Vena Cava Extension: Can Classification Be Optimized to Predict Perioperative Outcomes?

Ambiguity exists regarding the definition of a level III inferior vena cava tumor thrombus (IVC-TT), limiting comparisons between open and minimally-invasive series. We assessed 253 patients who underwent radical nephrectomy with IVC-TT from 2000-2015 and proposed a modified classification based on associations between intraoperative IVC clamp position and need for cardiopulmonary bypass with complications, length of stay, and blood transfusions. Predictive ability of the modified system was not meaningfully improved (AUCs 0.59–0.58; 0.61–0.61; 0.72–0.72). Nevertheless, we advocate for standardization of the border of a level III thrombus at or above the major hepatic veins to facilitate meaningful comparisons between techniques.